Cardiac arrest, or heart fibrillation, is the rapid and uncoordinated contraction of the cardiac muscle. The use of external defibrillators to restore the heartbeat to its normal pace through the application of an electrical shock is a well recognized and important tool for resuscitating patients. External defibrillation is typically used in emergency settings in which the patient is either unconscious or otherwise unable to communicate.
Automated external defibrillators or AEDs are used by police officers, paramedics and other first-responder emergency medical technicians to resuscitate patients in fibrillation. It is important that the AEDs carried by these technicians be continuously operational and ready for use on a moments notice. It is essential that in a high stress situation of cardiac arrest, the technician be able to focus on the patient and not on what buttons need be depressed to turn on the AED. Studies have shown that the chances of successfully resuscitating a patient decreases approximately ten percent per minute following fibrillation, thus the consequences of having to fumble with a "power on" switch that may be confusingly placed among a multitude of switches can have severe consequences. There is, therefore, a need for a lid open detection circuit that is capable of reliably powering on an AED without the need for actual depression of a "power on" button.